THANK YOU. I'm currently writing a manual for a DAW and was baffled by the FM in a synth in it because I've pretty much only had experience with linear FM and had absolutely no idea what it was doing. It is INSANE that I've never heard of this distinction in FM types before. There seems to be shockingly little discussion about it online.
I’ve often wondered why the FM mode of my analogue synth doesn’t sound the same as even a 2-op patch, you’ve made it super clear! Also wow, people weren’t kidding when they said simply changing which operators are audible takes a few minutes in a traditional DX synth - in my Opsix I would’ve slid the faders for those operators down in two seconds! Of course I’d read it was an easier and faster user interface but I hadn’t looked into just how much that is true. Thanks!
For someone studying eurorack modular synthesis this is a very nice inspiring video. Be it someone just starting or as a reminder review of a seasoned person. Thank you.
I knew there was a difference between linear and exponential FM but, honestly, only because everyone talked about it. And of course I could hear the difference between "analog FM" and "digital FM". But never really understood the concept. Now I do, thank you for making this vid and compliments for your great explanation!
This synthesis method was also used in some arcade, console and PC videogames in form of the YM2151, YM2612 or YM3812 yamaha sound chips used during 80s and 90s. They bring me such good memories of my childhood...
Thank you so much for that explanation! Realised i've been going about it all wrong trying to build fm in puredata and applied this theory and its sounds worlds beyond now! BRILLIANT!
at last i understand FM! ive been patching my moog dfam's pitch envelope into my mother-32's linear fm input to create a pseudo sidechain effect - whenever a kick drum hits, the frequency of the mother 32 (for example in a bassline) bends upwards a little depending on how much of the envelope i let through. it gets even better when putting the envelope through an inverter so that the linear fm causes the frequency to bend downwards, out of audible range. thank you for this great video. i look forward to more of your videos.
Keith! Excellent vid thank you! I'm a DSI Pro 2 owner and just found out about the Linear FM update for the Pro 2 firmware and I needed to know what the hell that even meant!
i love this guy, he looks like he stole all the infinity stones. Thankfully some people are geeks on this subject and they give us "big guns" like he say. thanks for the video, very interesting.
Great video - the DX7 actually uses Phase Modulation (PM) because it has a carrier wave that is used to alter the phase angle between them. Although PM is an intermediate step of achieving FM, FM is probably more just a marketing term by Yamaha. Either PM or FM are really just special cases of quadrature amplitude modulation (QAM) (mathematically speaking). I often joke by asking people how their QAM synth is going - you get some funny looks :) Keep it up - maybe do a video on Ring Modulators .... this is right up the same alleyway!
FM is frequency modulation, AM of course is amplitude modulation. These are not the same, and do not sound the same. You'll have to do some explaining to show how a quadrature generator is the same as phase modulation.
Doug Brown I didn't say they were the same not did I say that FM was AM. I said mathematically they (PM and FM) are special cases of QAM. more info here: en.m.wikipedia.org/wiki/Phase_modulation
I am sure phase modulation is a reasonable way to explain DX7 style synthesis, because the equations clearly show that phase modulation is what's happening. I am not sure why they call FM a special case of QAM, but I am not disputing it - I just can't explain it :)
Instant frequency is the first derivative of instant phase, so when both carrier and modulating signal are sine waves, there is no difference between FM and PM, because they produce the same signal. And don't believe Wikipedia, QAM is not superset of FM and PM. QAM is a digital modulation scheme with sine carrier, while FM and PM are analog modulation schemes with any periodical carrier. What you meant as QAM is not modulation at all, it is just one of the ways to represent narrowband signals, in terms of complex envelope.
Drizzgit , while there's no really robust analog FM sound synthesizer, this is a a hardware limitation, not a conceptual mismatch. Analog VCOs that respond quickly enough to changes in control voltage are just impractical for musical equipment. However the _principal_ of frequency/phase modulation is analog. I.e. it discusses only waveforms and analog signals.
I'm glad you liked the video. I'm currently working on a new video, showing how to develop a bass FM patch, with all of the nitty gritty details explained.
That was very well explained, thank you! Could you shed some light on through-zero FM? What it is, how to achieve it and how it sounds different from regular linear FM?
Basically linear but you can crank the fm depth all the way without it sounding as gritty as normal linear fm. As the name suggests it allows to go beyond 0 (negative frequencies).
Great video! you did a great job clarifying the differences between lin and exp FM. I haven't ever bothered to do too much in the way of FM, but I tried some on my modular. Unfortunately the analog oscillators weren't perfect enough to get sounds similar to what you got on the DX11. Got me tempted to pick up a similar keyboard just to explore more along the lines of FM. Unfortunately most FM synths seem to have poor interfaces.
Opsix is the way to go if you want the structure of FM reflected in the user interface with almost one knob per function. The refaceDX someone else mentioned was certainly very good when it was new but compared to the Opsix there’s a lot more menu diving. Plus it’s just touch pads instead of knobs and faders.
Some people say, Yamaha's FM synthesis is not really FM, but Phase Modulation, which I don't really get because frequency modulation is achieved by speeding and slowing (or even reversing backwards) a phase of a wave (I guess). So many things still to learn about my TX81z, but meanwhile I understood one thing. I need to learn about various natural (physical) ways harmonics "grow" from musical instruments too. E.g.: string instruments produce harmonics that are slightly sharper (therefore inharmonious) than basic note fq (thickness of a string). I don't know if that can be reproduced with DX synths, and there are some softsynths that can do that, but I can tell it's very difficult to find analytic texts about where in nature (I mean in physical systems like musical instruments, primarly) a frequency modulation occures, ...and how (and the ones that can be mimicked by FM, like cutoff filter sweeps)
Thanks this was really informative. The sound at the beginning of the video was a bit odd for me, but the explanation was crystal clear. Thanks again!!...
Great video, thanks, Keith! At around 6:50, you mention that Osc 4 in the vertical line algorithm oscillates itself. Could you please expand on that? I'm not sure I understand. Thanks again!
Hi Andrew. That's a great question! In linear FM, when an operator is in a feedback loop, the amplitude of the oscillator output will modulate the frequency of that same oscillator. In this case, as the amplitude of oscillator 4 increases, it will cause the pitch of oscillator 4 to go up. As the amplitude of oscillator 4 decreases, it will cause the pitch of oscillator 4 to go down. Since oscillator 4 is a sine wave (which has an amplitude that is constantly increasing and decreasing), it will cause the pitch of oscillator 4 to go up and down at the same rate. The overall amount of feedback is controlled by 3 things: the fixed output level of the operator, the feedback amount, and an amplitude envelope that is applied to the operator.
I'm quite confused about some videos that sate that FM synthesis is truly Phase modulation. So I'm not sure if they are wrong and it is just a problem fo confusing Linear and Exponential FM
![Alternate Tunings With The [KRM-100] MIDI-CV-Arpeggiator](http://i.ytimg.com/vi/yzl2V2ym-fQ/mqdefault.jpg)
![Alternate Tunings With The [KRM-100] MIDI-CV-Arpeggiator](/img/tr.png)
THANK YOU. I'm currently writing a manual for a DAW and was baffled by the FM in a synth in it because I've pretty much only had experience with linear FM and had absolutely no idea what it was doing. It is INSANE that I've never heard of this distinction in FM types before. There seems to be shockingly little discussion about it online.
You are most welcome. I'm glad you found my video useful.
I’ve often wondered why the FM mode of my analogue synth doesn’t sound the same as even a 2-op patch, you’ve made it super clear!
Also wow, people weren’t kidding when they said simply changing which operators are audible takes a few minutes in a traditional DX synth - in my Opsix I would’ve slid the faders for those operators down in two seconds! Of course I’d read it was an easier and faster user interface but I hadn’t looked into just how much that is true.
Thanks!
Best explanation of this subject on the net. Big up Keith!
Just found u channel. Great stuff brother.
FM is so weird. Musically, technically, everything-ly. This was great. I hope you can do a video with a Digitone one day.
Best explanation on exponential fm on RUclips. Tried many vids and struggled. Thanks so much!
Это лучшее разъяснение из всех, какие я когда-либо встречал! Спасибо, Keith! 👍👍👍
For someone studying eurorack modular synthesis this is a very nice inspiring video. Be it someone just starting or as a reminder review of a seasoned person. Thank you.
Thanks Chas. I'm glad you found this video inspiring.
I knew there was a difference between linear and exponential FM but, honestly, only because everyone talked about it.
And of course I could hear the difference between "analog FM" and "digital FM". But never really understood the concept.
Now I do, thank you for making this vid and compliments for your great explanation!
I like the pace of your videos. Also, this one is very informative - thanks for posting it!
This synthesis method was also used in some arcade, console and PC videogames in form of the YM2151, YM2612 or YM3812 yamaha sound chips used during 80s and 90s. They bring me such good memories of my childhood...
Explained sega genesis and CX16 music to me quite well! (Both had a PSG inside them and a PCM channel too)
Get famitracker and make your own chiptune tracks!
Thank you so much for that explanation! Realised i've been going about it all wrong trying to build fm in puredata and applied this theory and its sounds worlds beyond now! BRILLIANT!
Best demonstration ever. I learned something. I love it.
I'm glad you got something out of it! Thanks.
I really appreciate your FM videos.
so important to understand and demystify, you are a great communicator.
Thanks, Keith, that was really informative and answered the questions I had regarding the difference between the two types of FM.
Thanks for making this video. It was a great explanation of the difference between exponential and linear FM.
Thanks. Still not sure whether I want to tackle FM but you've definitely made it more approachable.
I'm glad I could add some clarity.
at last i understand FM! ive been patching my moog dfam's pitch envelope into my mother-32's linear fm input to create a pseudo sidechain effect - whenever a kick drum hits, the frequency of the mother 32 (for example in a bassline) bends upwards a little depending on how much of the envelope i let through. it gets even better when putting the envelope through an inverter so that the linear fm causes the frequency to bend downwards, out of audible range. thank you for this great video. i look forward to more of your videos.
Keith! Excellent vid thank you! I'm a DSI Pro 2 owner and just found out about the Linear FM update for the Pro 2 firmware and I needed to know what the hell that even meant!
Underrated video man. Great job, liked!
Thank you!
Amazingly clear and logic explanation. Best, by far. Congratulations, keep on creating amazing content!
Thanks for the compliment Corneliu.
Thank you! Now that you've explained the difference I'm left wondering why I didn't figure this out already
Best you tube video I've seen in ages. Thanks :) great explanation. The mist has cleared.
FM synthesis tutorial, preparing for Volca FM (feat. Nord Modular G2)
i love this guy, he looks like he stole all the infinity stones. Thankfully some people are geeks on this subject and they give us "big guns" like he say. thanks for the video, very interesting.
Best video on FM synthesis ever. Thank you!
Your level of knowledge is a very enviable thing. I can’t wait to watch more!!
Thanks for the comment Grant.
Well explained and informative video
Thanks Vitor, I'm glad to pass on what I know.
Great video - the DX7 actually uses Phase Modulation (PM) because it has a carrier wave that is used to alter the phase angle between them. Although PM is an intermediate step of achieving FM, FM is probably more just a marketing term by Yamaha. Either PM or FM are really just special cases of quadrature amplitude modulation (QAM) (mathematically speaking). I often joke by asking people how their QAM synth is going - you get some funny looks :)
Keep it up - maybe do a video on Ring Modulators .... this is right up the same alleyway!
FM is frequency modulation, AM of course is amplitude modulation. These are not the same, and do not sound the same. You'll have to do some explaining to show how a quadrature generator is the same as phase modulation.
Doug Brown I didn't say they were the same not did I say that FM was AM. I said mathematically they (PM and FM) are special cases of QAM. more info here: en.m.wikipedia.org/wiki/Phase_modulation
I am sure phase modulation is a reasonable way to explain DX7 style synthesis, because the equations clearly show that phase modulation is what's happening. I am not sure why they call FM a special case of QAM, but I am not disputing it - I just can't explain it :)
Instant frequency is the first derivative of instant phase, so when both carrier and modulating signal are sine waves, there is no difference between FM and PM, because they produce the same signal. And don't believe Wikipedia, QAM is not superset of FM and PM. QAM is a digital modulation scheme with sine carrier, while FM and PM are analog modulation schemes with any periodical carrier. What you meant as QAM is not modulation at all, it is just one of the ways to represent narrowband signals, in terms of complex envelope.
Drizzgit , while there's no really robust analog FM sound synthesizer, this is a a hardware limitation, not a conceptual mismatch. Analog VCOs that respond quickly enough to changes in control voltage are just impractical for musical equipment.
However the _principal_ of frequency/phase modulation is analog. I.e. it discusses only waveforms and analog signals.
I just bought a Yamaha TX-802, and I'd love to watch more videos like this to explain FM synthesis. Thank you! This was really great.
I'm glad you liked the video. I'm currently working on a new video, showing how to develop a bass FM patch, with all of the nitty gritty details explained.
Great!
Thanks Keith,
simply Wonderful
Great explanation and demonstration. I hit subscribe about a minute and a half in. Checking out your other videos now.
Thanks for the subscribe Troy!
thanks for this knowledge..great vid..hope for more.
Great video Keith! Keep up the good work!
No nonsense. Seriously wholesome.
easy to follow, very informative
This was very helpful for making identifying FM types!
You are welcome, Preston.
that clears up
Amazing, very clear & no bs explanation... thanks!
Very clear explanations - thank you. Very well designed video.
excellent concepts thanks for this
This actually made things clearer. Thanks.
Fantastic video. Such a simple and direct explanation. Thank you!
more instruction classes on fm please!!!!! basic string/pads etc - these are great videos!
SAME!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
LOVED IT
That was very well explained, thank you! Could you shed some light on through-zero FM? What it is, how to achieve it and how it sounds different from regular linear FM?
Basically linear but you can crank the fm depth all the way without it sounding as gritty as normal linear fm. As the name suggests it allows to go beyond 0 (negative frequencies).
Thank you. Just, Thank you.
wonderful video and extremely clear explanation, thank you ☺️
I would have to agree with the Lumberjack man
You are an awesome teacher!
Well explained 👍
Great video
Very useful. Thank you.
Great video! you did a great job clarifying the differences between lin and exp FM. I haven't ever bothered to do too much in the way of FM, but I tried some on my modular. Unfortunately the analog oscillators weren't perfect enough to get sounds similar to what you got on the DX11. Got me tempted to pick up a similar keyboard just to explore more along the lines of FM. Unfortunately most FM synths seem to have poor interfaces.
you should check out yamaha's DX-Reface, it's got a good user interface with 4 operators
Cylonix Shapeshifter from intelijel is a beast of an FM complex osc as is Endorphines Furthrrrr generator.
Opsix is the way to go if you want the structure of FM reflected in the user interface with almost one knob per function.
The refaceDX someone else mentioned was certainly very good when it was new but compared to the Opsix there’s a lot more menu diving. Plus it’s just touch pads instead of knobs and faders.
Very interesting. Thanks for this easy to follow and understand video.
Great!
Thank you!
Great video, Keith. Keep these coming !
Nice explanation, thanks 👍
aweasome thanks
Thank you. Great video :) Made perfect sense. Knowledge increased ✔
Great video! Looking forward to more hands on exporation on fm synthesis.
This video topic/title is why I just sent a Subscription to your Channel ;)
Thank you Reso Factor!
great video(s).
Some people say, Yamaha's FM synthesis is not really FM, but Phase Modulation, which I don't really get because frequency modulation is achieved by speeding and slowing (or even reversing backwards) a phase of a wave (I guess).
So many things still to learn about my TX81z, but meanwhile I understood one thing. I need to learn about various natural (physical) ways harmonics "grow" from musical instruments too. E.g.: string instruments produce harmonics that are slightly sharper (therefore inharmonious) than basic note fq (thickness of a string).
I don't know if that can be reproduced with DX synths, and there are some softsynths that can do that, but I can tell it's very difficult to find analytic texts about where in nature (I mean in physical systems like musical instruments, primarly) a frequency modulation occures, ...and how (and the ones that can be mimicked by FM, like cutoff filter sweeps)
Fascinating. Brilliantly explained.
Thanks this was really informative.
The sound at the beginning of the video was a bit odd for me, but the explanation was crystal clear. Thanks again!!...
superb thanks
You're welcome Bill.
Very lightning explanation man. Thank You!
Nice job man, thank you for the video
Great!
I've always wondered what the difference was !!
Thanks mate :)
Great explanation.
Thanks
Thank you very much Keith
Great Job
great video, thank you
You are very welcome Nic.
Hey! The Edirol UA-25! Nice to see one more around
Thanks so much!
Awesome fm sound effects are alway's complex to make but worth it.
Great video!
Great video, thanks, Keith! At around 6:50, you mention that Osc 4 in the vertical line algorithm oscillates itself. Could you please expand on that? I'm not sure I understand. Thanks again!
Hi Andrew. That's a great question! In linear FM, when an operator is in a feedback loop, the amplitude of the oscillator output will modulate the frequency of that same oscillator. In this case, as the amplitude of oscillator 4 increases, it will cause the pitch of oscillator 4 to go up. As the amplitude of oscillator 4 decreases, it will cause the pitch of oscillator 4 to go down. Since oscillator 4 is a sine wave (which has an amplitude that is constantly increasing and decreasing), it will cause the pitch of oscillator 4 to go up and down at the same rate.
The overall amount of feedback is controlled by 3 things: the fixed output level of the operator, the feedback amount, and an amplitude envelope that is applied to the operator.
Very helpful explanation, thanks.
nice explainations
Great vid
awesome vid Keith
Hey thanks man, this is very clear ...
Great vid I've been looking to find. Could you plz post other vids to explain other types of algorithms?
Thanks!
Hey thank you for the information, i cleared my doubts respect this theme.
Thanks for the kind words Sir William.
I'm quite confused about some videos that sate that FM synthesis is truly Phase modulation. So I'm not sure if they are wrong and it is just a problem fo confusing Linear and Exponential FM
Thanks a bunch! Great Video!
Great explanation. Thanks!
Finally, I get it!! Thank you
You are welcome.
great explanation, thanks keith!
great explanation! Thanks.
thank you a lot, very informative video
Ok , got it ! Now going back to my DX7 ll with Grey Matter E ! Thanks .
So : for simplify :
Exponential is modulation in term of pitch
Linear is modulation in term of Hertz
I finally have the response ! Thanks !
Great video, Thank you!